<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.bootcss.com/vue/2.6.10/vue.js"></script>
</head>
<body>
    <div id="app">
        {{msg}}
        <p v-for="item of arr">{{item}}</p>
    </div>
    <script>
        var vm=new Vue({
            data:{
                msg:"hello world",
                arr:[1,2,3]
            }
        }).$mount('#app')
    </script>
    <!-- 在console中使用vm.msg="good"可以直接更改msg里面的东西 -->
</body>
</html>